fix: TUIウィジェットの表示を修正

- diff表示の修正
- historyリストの修正
- markdown表示の修正

Co-Authored-By: Claude <noreply@anthropic.com>

crates/miyabi-tui/src/ui/widgets/diff.rs

@@ -1,14 +1,70 @@
-//! Diff viewer widget placeholder.
+//! Diff viewer widget for displaying file changes.
 //!
-//! This will eventually wrap `diff_render.rs` for reuse across overlays.
+//! Wraps `diff_render.rs` for reuse across overlays with scrolling support.
 
-use ratatui::layout::Rect;
-use ratatui::Frame;
+use ratatui::{
+    layout::Rect,
+    widgets::{Block, Borders, Paragraph, Wrap},
+    Frame,
+};
 
-use crate::diff_render::FileDiff;
+use crate::diff_render::{DiffRender, FileDiff};
 
-/// Render a diff within the given area.
-pub fn render_diff_widget(frame: &mut Frame, area: Rect, diff: &FileDiff) {
-    let _ = (frame, area, diff);
-    // TODO: integrate syntax highlighting and line numbers.
+/// Properties for rendering a diff widget
+pub struct DiffWidgetProps {
+    /// The file diff to display
+    pub diff: FileDiff,
+    /// Current scroll offset
+    pub scroll: u16,
+    /// Optional title for the block
+    pub title: Option<String>,
+}
+
+/// Render a diff within the given area with scrolling support.
+pub fn render_diff_widget(frame: &mut Frame, area: Rect, diff: &FileDiff) {
+    render_diff_widget_with_scroll(frame, area, diff, 0, None);
+}
+
+/// Render a diff with scroll offset and optional title.
+pub fn render_diff_widget_with_scroll(
+    frame: &mut Frame,
+    area: Rect,
+    diff: &FileDiff,
+    scroll: u16,
+    title: Option<&str>,
+) {
+    // Create a DiffRender with the single file
+    let mut renderer = DiffRender::new();
+    renderer.files.push(diff.clone());
+    
+    // Get rendered lines
+    let lines = renderer.render();
+    
+    // Create block with optional title
+    let block = if let Some(t) = title {
+        Block::default()
+            .borders(Borders::ALL)
+            .title(t.to_string())
+    } else {
+        Block::default()
+            .borders(Borders::ALL)
+            .title(format!("{} → {}", diff.old_path, diff.new_path))
+    };
+    
+    // Create paragraph with scroll
+    let paragraph = Paragraph::new(lines)
+        .block(block)
+        .wrap(Wrap { trim: false })
+        .scroll((scroll, 0));
+    
+    frame.render_widget(paragraph, area);
+}
+
+/// Calculate the total number of lines in a diff for scroll bounds
+pub fn diff_line_count(diff: &FileDiff) -> usize {
+    let mut count = 1; // File header
+    for hunk in &diff.hunks {
+        count += hunk.lines.len();
+    }
+    count
 }

crates/miyabi-tui/src/ui/widgets/history_list.rs

@@ -3,12 +3,15 @@
 //! Intended to wrap `HistoryCell` rendering with consistent padding and theming.
 
 use ratatui::{
-    layout::Rect,
-    widgets::{Block, Borders},
+    layout::{Alignment, Rect},
+    style::Style,
+    text::Line,
+    widgets::{Block, Borders, List, ListItem, Paragraph},
     Frame,
 };
 
 use crate::history_cell::HistoryCell;
+use crate::ui::colors;
 
 /// Properties required to render the history list.
 pub struct HistoryListProps<'a> {
@@ -21,10 +24,53 @@ pub struct HistoryList;
 
 impl HistoryList {
     pub fn render(frame: &mut Frame, area: Rect, props: HistoryListProps<'_>) {
-        let block = Block::default().borders(Borders::ALL);
+        let block = Block::default()
+            .borders(Borders::ALL)
+            .border_style(Style::default().fg(colors::BORDER))
+            .title("History");
+        let inner = block.inner(area);
         frame.render_widget(block, area);
 
-        let _ = props;
-        // TODO: integrate with virtualized list + markdown rendering.
+        if inner.height == 0 || inner.width == 0 {
+            return;
+        }
+
+        if props.items.is_empty() {
+            let empty = Paragraph::new("No history yet")
+                .style(Style::default().fg(colors::COMMENT))
+                .alignment(Alignment::Center);
+            frame.render_widget(empty, inner);
+            return;
+        }
+
+        let scroll = props.scroll as usize;
+        let max_lines = inner.height as usize;
+        let mut visible_lines: Vec<Line> = Vec::with_capacity(max_lines);
+        let mut line_index = 0usize;
+
+        'outer: for (idx, cell) in props.items.iter().enumerate() {
+            let mut rendered = cell.render(inner.width);
+            if idx + 1 < props.items.len() {
+                rendered.push(Line::from(""));
+            }
+
+            for line in rendered {
+                if line_index >= scroll {
+                    visible_lines.push(line);
+                    if visible_lines.len() >= max_lines {
+                        break 'outer;
+                    }
+                }
+                line_index += 1;
+            }
+        }
+
+        let list_items: Vec<ListItem> = visible_lines
+            .into_iter()
+            .map(ListItem::new)
+            .collect();
+
+        let list = List::new(list_items).style(Style::default().fg(colors::FG));
+        frame.render_widget(list, inner);
     }
 }

crates/miyabi-tui/src/ui/widgets/markdown.rs

@@ -3,13 +3,62 @@
 //! This file is the landing zone for `markdown_stream` integration to keep
 //! rendering logic out of `history_cell.rs`.
 
-use ratatui::layout::Rect;
-use ratatui::Frame;
+use ratatui::{
+    layout::Rect,
+    style::{Modifier, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph, Wrap},
+    Frame,
+};
 
+use crate::markdown_render::MarkdownRenderer;
 use crate::markdown_stream::MarkdownStream;
+use crate::ui::colors;
 
 /// Render a markdown stream into the provided frame area.
 pub fn render_stream(frame: &mut Frame, area: Rect, stream: &MarkdownStream) {
-    let _ = (frame, area, stream);
-    // TODO: reuse MarkdownRenderer and add code block scroll support.
+    let block = Block::default()
+        .borders(Borders::ALL)
+        .border_style(Style::default().fg(colors::BORDER))
+        .title("Markdown");
+
+    let inner_height = area.height.saturating_sub(2) as usize;
+
+    let mut lines = if stream.is_empty() {
+        vec![Line::from(Span::styled(
+            "Waiting for response...",
+            Style::default().fg(colors::COMMENT),
+        ))]
+    } else {
+        let renderer = MarkdownRenderer::default();
+        renderer.render(stream.content())
+    };
+
+    if stream.is_streaming() {
+        if let Some(last) = lines.last_mut() {
+            last.spans.push(Span::styled(
+                "▌",
+                Style::default()
+                    .fg(colors::FG)
+                    .add_modifier(Modifier::SLOW_BLINK),
+            ));
+        } else {
+            lines.push(Line::from(Span::styled(
+                "▌",
+                Style::default()
+                    .fg(colors::FG)
+                    .add_modifier(Modifier::SLOW_BLINK),
+            )));
+        }
+    }
+
+    let max_offset = lines.len().saturating_sub(inner_height.max(1));
+    let offset = stream.scroll_offset().min(max_offset);
+
+    let paragraph = Paragraph::new(lines)
+        .block(block)
+        .wrap(Wrap { trim: false })
+        .scroll((offset as u16, 0));
+
+    frame.render_widget(paragraph, area);
 }